Abuzzahab 1982.

Methods	Randomisation: implied randomisation. Blinding: double‐blind. Duration: 24 weeks. Design: parallel. Location: not indicated. Setting: outpatients.
Participants	Diagnosis: schizophrenia. N = 57. Gender (N = 46): 20M, 16F. Age: mean 35.5 years. History: duration stable: not indicated, duration of illness: mean 9 years, number of previous hospitalisations: not indicated, age at onset: not indicated, severity of illness: not indicated, baseline antipsychotic dose: not indicated.
Interventions	1. Haloperidol: fixed/flexible dose: not indicated, dose range: 5 mg to 40 mg/day, mean dose: 17.5 mg/day. N = 22. 2. Thiothixene: fixed/flexible dose: not indicated, dose range: 10 mg to 80 mg/day, mean dose: 31.8 mg/day. N = 24.   Rescue medication: “Antiparkinsonian drugs were permitted”
Outcomes	Examined: Leaving the study early due to any reason. Adverse effects: at least one adverse effect, akathisia, rigor, tremor, weight gain. Unable to use: Clinically important response to treatment: Investigator global evaluation (no raw data available). Global state general: Evaluation of Social Functioning (ESFR) (no total score available, no SDs available). Mental state general: Brief Psychiatric Rating Scale (BPRS) (no SDs available and no imputation method could be applied). Mental state specific: Hamilton Psychiatric Rating Scale for depression (HPRSD) (no SDs available and no imputation method could be applied). Mental state specific: ZUNG scale (self‐rating depression scale) (no raw data available). Behaviour: Nurses´ Observation Scale for Inpatient Evaluation (NOSIE) (mentioned in the abstract, but not in the methods and results section of the publication).
Notes	57 participants were randomised, but participants were only included in the analyses if they “had at least 10 days of therapy.”
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No randomisation mentioned in the publication, but the trial was described as “double‐blind.” Thus, it was implied that the study was randomised.
Allocation concealment (selection bias)	Unclear risk	No further details.
Blinding (performance bias and detection bias) (performance bias)	Low risk	“Double‐blind”. “The study medications were administered as identical‐appearing capsules.”
Blinding (performance bias and detection bias) (detection bias)	Unclear risk	“Double‐blind”. No further details.
Incomplete outcome data (attrition bias) All outcomes	High risk	The overall‐attrition was high: 31 of 57 participants (54.4%) left the trial early. The trial authors indicated that 15 of 29 participants (51.7%) in the haloperidol‐group and 16 of 28 participants (57.1%) in the thiothixene‐group discontinued the drug treatment prematurely. Modified completers analyses were used (“all patients evaluated had at least 10 days of therapy”).
Selective reporting (reporting bias)	High risk	The outcome data were not fully addressed (no total score or SDs for the BPRS, HPRSD, ESFR, and investigator global evaluation; no raw data for the ZUNG scale; the NOSIE scale is mentioned in the abstract but not in the methods and results section of the publication). There was no information regarding the number of participants who received a medication with antiparkinson drugs in each group; only for the whole study sample of the 46 analysed participants.
Other bias	Unclear risk	Insufficient information to assess whether an important risk of bias exists.